CAJ | 학술논문

为评估奶牛乳头长度和乳头末端健康状况在奶业生产中的重要性，本研究对山西省奶牛场的514头泌乳牛乳头长度和乳头末端状况进行评分，并收集了该场2013年6月24日的DHI数据。采用固定模型分析牛只泌乳阶段、胎次、乳头长度和乳头末端状况四个因子对产奶量和体细胞数（SCC）的影响。经抽样分析发现，该牛场泌乳牛群乳头长度集中在4～6cm。乳头长度短于4cm的个体有22头（6.6%），最长乳头超过6cm的个体有53头（15.8%）。与乳头长度为4～6cm的牛只相比，乳头长度超过6cm或短于4cm的奶牛，其乳头末端健康状况显著下降（P＜0.05）。该牛群乳头末端评分的均值为2.25分，参照文献评价乳头健康的标准，该场泌乳牛乳头健康状况良好。经对前后乳区的乳头末端损伤程度进行分析，表明奶牛后乳区乳头末端状况极显著好于前乳区（P＜0.01）。乳头长度和乳头末端状况对产奶量和SCC的影响不显著（P＞0.05），但乳头过长时奶牛平均SCC比正常个体高出5.8万个/mL。乳头有损伤的个体较乳头健康奶牛SCC的均值高出2.2万个/m L。评价牛群的乳头长度和乳头末端状况有助于了解牛群的乳房健康状况，可为牛群管理提供有用建议。
위평고내우유두장도화유두말단건강상황재내업생산중적중요성，본연구대산서성내우장적514두비유우유두장도화유두말단상황진행평분，병수집료해장2013년6월24일적DHI수거。채용고정모형분석우지비유계단、태차、유두장도화유두말단상황사개인자대산내량화체세포수（SCC）적영향。경추양분석발현，해우장비유우군유두장도집중재4～6cm。유두장도단우4cm적개체유22두（6.6%），최장유두초과6cm적개체유53두（15.8%）。여유두장도위4～6cm적우지상비，유두장도초과6cm혹단우4cm적내우，기유두말단건강상황현저하강（P＜0.05）。해우군유두말단평분적균치위2.25분，삼조문헌평개유두건강적표준，해장비유우유두건강상황량호。경대전후유구적유두말단손상정도진행분석，표명내우후유구유두말단상황겁현저호우전유구（P＜0.01）。유두장도화유두말단상황대산내량화SCC적영향불현저（P＞0.05），단유두과장시내우평균SCC비정상개체고출5.8만개/mL。유두유손상적개체교유두건강내우SCC적균치고출2.2만개/m L。평개우군적유두장도화유두말단상황유조우료해우군적유방건강상황，가위우군관리제공유용건의。
To assess the importance of teat length and teat-ends condition in dairy production, we scored teat-length and teat-ends condition of 514 lactating cows in a Holstein dairy farm in Shanxi. DHI data measured on June 24th, 2013 was also collected. A ifxed model was employed to analyze the impact of four factors (lactation stage, parity, teat-length and teat-end condition) on milk yield and somatic cell count. A random sample analysis of teat length indicated that the most of teat length were within a range of 4~6cm. The number of cows with teat shorter than 4cm was 22 (6.6%), and 53 (15.8%) cows had the longest teat over 6cm. There were signiifcant differences (P<0.05) of health status between teat-end health status with different teat-lengths. Compared with the 4~6cm teat ,teats longer than 6cm or shorter than 4cm have a signiifcant increase in the probability of teat injury. The mean score of the teat-end condition of this population was 2.25.The average teat-end health status indicated that the teat-end of the whole dairy farm was in good health condition, based on the published standards of scoring teat-end health condition. The teat-end condition showed signiifcant difference (P<0.01) between the rear teats and front teats, and front teats were much more health than rear teats. The effect of the teat length and teat-end condition were not signiifcant on the milk yield and SCC(P>0.05). The average SCC of milking cow with longer teat were 58 000/mL higher than that of normal individuals. The mean SCC of individual with injured teats were 22 000/mL higher than that of individuals with healthy teats. Evaluating the teat length and teat-end condition helps ifnding out the health status of the dairy herd and provides useful suggestions for dairy herd management.